An antenna structure in which an antenna element is disposed on a hinge portion of a folding mobile terminal is known. In an antenna structure disclosed in Patent Document 1, an antenna element for a non-contact IC card is disposed on a cylindrical hinge portion. With this structure, stable wireless communication with a reader and writer can be ensured on both sides of a mobile terminal.
In an antenna structure disclosed in Patent Document 2, an antenna element formed by a ring conductor having a C-shaped cross section is disposed in a hinge portion. Capacitive coupling of the ring conductor to a metal rotation shaft can provide a wide-band antenna having a high degree of design freedom.
In an antenna structure disclosed in Patent Document 3, a hinge shaft is used as an element conductor. Using the hinge shaft as an element conductor makes it possible to reduce the size of a mobile terminal.
In an antenna structure disclosed in Patent Document 4, a hinge is used as a ground, and the hinge and an antenna element operate as a dipole antenna.
In an antenna structure disclosed in Patent Document 5, hinges are disposed at both ends of a rotation axis of a folding electronic device, and antenna elements are interposed between the hinges.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-214740
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2011-19211
Patent Document 3: International Publication No. 2009/139100
Patent Document 4: Japanese Unexamined Patent Application Publication No. 2011-239347
Patent Document 5: International Publication No. 2012/039879